Filling station stalwart Maxol has had to deal with everything from tough times amid cross-border fuel smuggling, to the rise of UK supermarket petrol in Northern Ireland.

But the family-owned business - which began in Belfast almost 100 years ago - is expanding here, and has just started work on its first motorway-style service station at Tannaghmore in Co Antrim.

At the helm since May, Co Down man Brian Donaldson now oversees a business which turns over €650m (£560m) a year, with 236 petrol stations across Ireland.

Brian (51) joined Maxol in 1986 as a graduate trainee, looking at customer profiling and consumer habits and behaviours.

And this year he's marking 30 years with the business.

The company now has 236 stations across Ireland - of which 113 are directly owned by Maxol - with around 100 of those in Northern Ireland. And the company has come a long way since William and James McMullan started their business at Middlepath Street in Belfast almost 100 years ago, where they delivered paraffin oil by horse and cart.

"The company is privately owned by the McMullan family, and is in the fourth generation. It's one of the true family businesses on the island of Ireland," Brian said.

And it's a business which has very strong heritage and roots in the province, with the family originally hailing from Limavady.

"The business has been evolving over the 100 year period. Really, my role in the business is to lead the overall organisation," Brian said.

"The other core aspect (of the company) is the lubricants business, which operates just outside Dublin."

"We also have a large business-to-business.

"Today, we employ around 80 people, and provide indirect employment for 1,500 people.

"In Northern Ireland we are market leaders in terms of fuel sales.

"It continues to be one of the most competitive regions in the UK and the island of Ireland."

But Maxol, as with others in the business, has also had to deal with hurdles along the way, including an influx of illegal laundered, and smuggled fuel.

"One of the big hits to Northern Ireland was laundered and smuggled fuel (between 1996 and the mid 2000s).

"We dropped to about 70 sites...it has taken that time to get back up."

Brian said Maxol was faced with the situation in which it was going up against smaller businesses which were selling the laundered fuel.

"Businesses couldn't compete with businesses that were selling the fuel. We were seen as being the Volkswagen of our industry."

It's tackled stiff competition here in the last few decades, including the influx of supermarket fuel, which entered the Northern Ireland market in the mid 1990s.

"Northern Ireland is such a tight, dynamic market. It's tight and competitive, as you have all the UK multiples.

"In 1995, Tesco opened with fuel at Yorkgate (in Belfast). That was a change in the market. From our perspective, we welcome competition."

Maxol also underwent a rebrand between 2011 and 2012.

"We realised we needed to do a root and branch review of the brand," Brian said.

Originally from just outside Comber in Co Down, Brian comes from a strong farming background.

Along with brother Michael and sister Linda, all three studied in England, with Brian attending Bradford University.

But he was the only one to come back to work in his native Northern Ireland.

"My father (Terry) felt strongly that we needed to fend for ourselves," Brian said.

His job now takes him between the company's Northern Ireland base in Mallusk, and the head office in Dublin.

Brian now lives in Templepatrick with his wife Alyson - who works for the Department of Education - and daughter Jessica (18) who just gone to university to study optometry.

"I wouldn't be doing the job without her (Alyson's) full support. I feel extremely privileged."

He's been with the company for his whole professional life, starting fresh out of university as a graduate trainee.

In that time, he's worked his way up across a variety of roles in the business, and was appointed as chief executive in May this year.

"I've been very lucky. I've pinged about within the organisation," he said.

On Brexit, he says: "I think to be quite honest, it is quite a concern to anyone who trades (across the border)."

He said any impact on the freedom of movement between Northern Ireland and the Republic would have the biggest single impact.

"I'm hoping through good common sense, with good government... that we can find a path that won't hinder business on the island."

Speaking about the firm's new large motorway service station just outside Antrim, Brian said: "We are going to develop a 'supersite' on this. It will have a very large forecourt and 80 car park spaces."

It will also feature its partner Spar, along with three other food stations.

That new style, which has already been adapted in the Republic, will put Maxol right up against rivals Applegreen.

Speaking about fuel prices here over the last few years, Brian says: "Fuel is a distress purchase. It's quite a large purchase.

"Today's consumers are very price savvy. At the end of the day, the prices will be determined by a number of factors, world factors.

"We buy refined product... those can be influenced by currency exchanges, global events, and that's when you are going to get spikes, and falls in fuel."

But he said the huge level of duty on fuel here, which is close to 70%, means huge fluctuations in the price aren't being felt by consumers at the pump.

When he's not at the helm of a £500m+ fuel and filling station business, Brian's also a dab hand in the garden.

"Outside of work, I do quite like gardening, and that probably comes from picking potatoes with my uncle.

"I like getting rid of the tie and the suits. I do like golf, and used to play a lot, but now it's finding the time. I also like watching Ulster - I'm a big rugby fan and like travelling down (to Dublin) to the big internationals.

"I also try to read as many newspapers as I can, to keep me up to speed."